<template>
    <div class="tags" v-if="showTags">
        <ul>
            <li class="tags-li" v-for="(item,index) in tagsList" :class="{'active': isActive(item.path)}" :key="index">
                <router-link :to="item.path" class="tags-li-title">
                    {{ item.title }}
                </router-link>
                <span class="tags-li-icon" @click="closeTags(index)">
                    <i class="el-icon-close"></i>
                </span>
            </li>
        </ul>
        <div class="tags-close-box">
            <el-dropdown @command="handleTags">
                <el-button size="mini" type="primary">标签选项
                    <i class="el-icon-arrow-down el-icon--right"></i>
                </el-button>
                <el-dropdown-menu size="small" slot="dropdown">
                    <el-dropdown-item command="other">关闭其他</el-dropdown-item>
                    <el-dropdown-item command="all">关闭所有</el-dropdown-item>
                </el-dropdown-menu>
            </el-dropdown>
        </div>
    </div>
</template>
<script>
import bus from "../style/js/bus.js";
export default {
    data() {
        return{
            tagsList: [],
        }
    },
    methods:{
        isActive(path){
            return path === this.$route.fullPath;
        },
        // 关闭当前标签
        closeTags(index){
            const delItem = this.tagsList.splice(index,1)[0];
            const item = this.tagsList[index]?this.tagsList[index]:this.tagsList[index-1];

            if(item) {
                delItem.path === this.$route.fullPath && this.$router.push(item.path);
            }else {
                this.$router.push('/');
            }

        },
        // 关闭所有标签
        closeAll(){
            this.tagsList = [];
            this.$router.push('/');
        },
        closeOther(){
            const curItem = this.tagsList.filter(item => {
                return item.path === this.$route.fullPath;
            })
            this.tagsList = curItem;
        },
        // 设置标签
        setTags(route){
            const isExist = this.tagsList.some(item => {
                return item.path === route.fullPath;
            })
            if(!isExist){
                if(this.tagsList.length >= 8){
                    this.tagsList.shift();
                }
                this.tagsList.push({
                    title: route.meta.title,
                    path: route.fullPath,
                    name: route.matched[1].components.default.name

                })
            }
            bus.$emit('tags', this.tagsList);
        },
        handleTags(command){
            command === 'other'? this.closeOther():this.closeAll();
        }
    },
    computed: {
        showTags(){
            return this.tagsList.length > 0;
        }
    },
    watch: {
        $route(newValue, oldValue){
            this.setTags(newValue);
        }
    },
    created(){
        this.setTags(this.$route);
        bus.$on('close_current_tags', () =>{
            for (let i = 0, len=this.tagsList.length; i < len; i++){
                const item = this.tagsList[i];
                if(item.path === this.$route.fullPath){
                    if(i < len-1){
                        this.$router.push(this.tagsList[i+1].path);
                    }else if(i > 0){
                        this.$rouer.push(this.tagsList[i-1].path);
                    }else {
                        this.$router.push('/');
                    }
                    this.tagsList.splice(i, 1);
                    break;
                }
            }
        })
    }
}
</script>
<style>
.tags {
        position: relative;
        height: 30px;
        overflow: hidden;
        background: #fff;
        padding-right: 120px;
        box-shadow: 0 5px 10px #ddd;
    }

    .tags ul {
        box-sizing: border-box;
        width: 100%;
        height: 100%;
    }

    .tags-li {
        float: left;
        margin: 3px 5px 2px 3px;
        border-radius: 3px;
        font-size: 12px;
        overflow: hidden;
        cursor: pointer;
        height: 23px;
        line-height: 23px;
        border: 1px solid #e9eaec;
        background: #fff;
        padding: 0 5px 0 12px;
        vertical-align: middle;
        color: #666;
        -webkit-transition: all .3s ease-in;
        -moz-transition: all .3s ease-in;
        transition: all .3s ease-in;
    }

    .tags-li:not(.active):hover {
        background: #f8f8f8;
    }

    .tags-li.active {
        color: #fff;
    }

    .tags-li-title {
        float: left;
        max-width: 80px;
        overflow: hidden;
        white-space: nowrap;
        text-overflow: ellipsis;
        margin-right: 5px;
        color: #666;
    }

    .tags-li.active .tags-li-title {
        color: #fff;
    }

    .tags-close-box {
        position: absolute;
        right: 0;
        top: 0;
        box-sizing: border-box;
        padding-top: 1px;
        text-align: center;
        width: 110px;
        height: 30px;
        background: #fff;
        box-shadow: -3px 0 15px 3px rgba(0, 0, 0, .1);
        z-index: 10;
    }

</style>

